Renal function outcomes after laparoscopic renal cryoablation

Abstract

Background and Purpose: Laparoscopic cryoablation (LCA) has emerged as an alternative to conventional surgery for the management of a T(1) renal mass; however, only few data are available on its functional outcomes. We assessed renal function changes after LCA in patients with normal renal function (NRF) and preexisting chronic renal insufficiency (CRI). Patients and Methods: Data of consecutive patients who were undergoing LCA between 2000 and 2008 at Duke University Medical Center were analyzed. Renal function parameters were obtained preoperatively, at discharge, and at 6, 12, and 24 months postoperatively. Serum creatinine (sCr) levels and estimated glomerular filtration rates (eGFR) were compared over a 2-year follow-up. Results: Of 67 patients, 22 (33%) had CRI at baseline. These patients were older, had larger tumors (2.5 vs 2.0 cm, P = 0.039), and a higher incidence of multiple lesions (22.7% vs 4.4%, P=0.034). Compared with baseline, sCr was significantly increased and eGFR declined at discharge, 6, 12, and 24 months in both NRF and CRI groups. Median sCr increase was 0.1 mg/mL, eGFR declined by 4.2 mg/mL/1.73 m(2) in the CRI cohort and up to 8.8 mg/mL/1.73m(2) in NRF patients (all P < 0.05) during the follow-up. Compared with baseline, however, no significant changes were noted in the distribution of CRI categories at any time (all P > 0.05). Conclusions: A minimal decline in renal function can be appreciated in patients undergoing LCA at midterm follow-up. This decline is no higher in CRI than in NRF patients. LCA offers excellent renal function outcomes at 2 years follow-up. Specifically, in patients with CRI, LCA offers excellent preservation of renal function. Editorial CommentThe authors investigated an important question regarding new technological aspects of nephronsparing surgery for small renal masses. The investigators assessed renal function changes after Laparoscopic cryoablation (LCA) in patients with normal renal function (NRF) and preexisting chronic renal insufficiency (CRI). From a total of 67 patients, 22 (33%) had CRI at baseline.The study indicates a statistically significant decline in renal function after LCA in both NRF and CRI patients. This is in contrast with the data seen in CRI patients on the other. In the present study, renal function decline was more pronounced among patients with normal renal function preoperatively despite the latter group having smaller tumors and lower incidence of multifocal disease. Interestingly, the data may suggest that while renal function stabilized in CRI patients after LCA, a continuous decline may be observed in the NRF group over a 2-year follow-up period. This may be because of a more attentive dietary regimen and behavioral measures to preserve renal function undertaken by patients with preexisting CRI compared with their "healthy" counterparts. Despite the evident decline in renal function parameters, its clinical significance is questionable, because no marked changes in the distribution of CKD categories were noted at any time...